The program for which this application is a supplement consists of four multifaceted research projects which share a single overall objective: To define the anatomical bases and molecular mechanisms of seizures and anticonvulsant drugs. Specific objectives are: (1) to define the roles of cyclic AMP and cyclic GMP in seizure discharges and anticonvulsant drug mechanisms; (2) to determine the roles of specific neurotransmitters in focal epilepsy using a recently developed, sophisticated isotopic method for localizing seizure discharges in brain; (3) to define the effects of major anticonvulsant drugs on lipid synthesis of brain, liver and cultured glial and neuronal cells; and (4) to study the diagnostic potential of positron emitting transaxial tomography (PETT) for localizing seizure foci. This supplemental proposal in this application adds electrophysiological studies which will identify epileptogenic foci and functional areas in cerebral cortex and will define physiologic and morphological characteristics of individual cells, particularly glia, in brain tissue slices. These projects are closely interrelated and complementary. The program brings together several excellent investigators with a common interest in basic and clinical problems of epilepsy but with diverse skills and research interests. Our research should provide a greatly improved understanding of epilepsy and its treatment.